Articles
REDUCING NITRATE ACCUMULATION OF DIFFERENT VEGETABLES BY CONTROLLED-RELEASE FERTILIZER AND CHLORIDE APPLICATION
Article number
938_25
Pages
195 – 202
Language
English
Abstract
Reducing nitrate content of vegetables is considered to be an important preventing measure because of health considerations.
Use of ammonium containing controlled-release fertilizer was found to be suitable for reducing nitrate content of spinach and lettuce.
Chloride application was shown to further enhance the nitrate accumulation lowering effect of ammonium nutrition.
We conducted several experiments with the purpose of reducing nitrate content of different vegetables by concentrated (band or spot) application of 40-day type polyolefin coated diammonium phosphate (POC-DAP) supplemented with chloride application.
It was found that in wider surroundings of band or spot placements of POC-DAP, 15-21% of the water soluble nitrogen remained in ammonium form at harvest time.
Thus long-term ammonium nutrition could be carried out with this method.
In the POC-DAP + KCl treatments abundant chloride supply and reduced nitrate availability prompted lettuce plants to take up chloride in considerable amounts.
The investigated fertiliza¬tion method significantly decreased nitrate content of butterhead lettuce, endive, kohlrabi and garden radish.
However, yield was also decreased by the concentrated POC-DAP + KCl application in some of the experiments, especially in the case of kohlrabi.
As use of potassium chloride did not decrease yield of butterhead lettuce compared to potassium sulphate application, and a 20% reduction in the nitrogen dose also did not have unfavorable effect on the yield, yield reduction was attributed to the higher ammonium concentration.
Use of ammonium containing controlled-release fertilizer was found to be suitable for reducing nitrate content of spinach and lettuce.
Chloride application was shown to further enhance the nitrate accumulation lowering effect of ammonium nutrition.
We conducted several experiments with the purpose of reducing nitrate content of different vegetables by concentrated (band or spot) application of 40-day type polyolefin coated diammonium phosphate (POC-DAP) supplemented with chloride application.
It was found that in wider surroundings of band or spot placements of POC-DAP, 15-21% of the water soluble nitrogen remained in ammonium form at harvest time.
Thus long-term ammonium nutrition could be carried out with this method.
In the POC-DAP + KCl treatments abundant chloride supply and reduced nitrate availability prompted lettuce plants to take up chloride in considerable amounts.
The investigated fertiliza¬tion method significantly decreased nitrate content of butterhead lettuce, endive, kohlrabi and garden radish.
However, yield was also decreased by the concentrated POC-DAP + KCl application in some of the experiments, especially in the case of kohlrabi.
As use of potassium chloride did not decrease yield of butterhead lettuce compared to potassium sulphate application, and a 20% reduction in the nitrogen dose also did not have unfavorable effect on the yield, yield reduction was attributed to the higher ammonium concentration.
Authors
A. Ombódi, R. Pesti, A. Balogh, J. Dimény, C.K. Morikawa, M. Saigusa
Keywords
diammonium phosphate, potassium chloride, ammonium nutrition, butterhead lettuce, endive, kohlrabi, garden radish
Online Articles (69)